Objective is to compare the efficacy and safety of three different doses of BRL42810 with acyclovir in the treatment of patients with first episode genital herpes infection (includes primary and non-primary, also known as "initial genital herpes"). A randomized, double-blind, double-dummy, parallel-group study comparing three dose levels of oral BRL42810 when given three times daily for ten days and acylovir given five times daily for ten days in treatment of first episode genital herpes infection.